Resilient Data Delivery Presentation at SmallSat Europe
- May 27
- 4 min read
Updated: May 29
KenCast Presented Resilient Data Delivery for SmallSat and Hybrid Space–Ground Architectures May 27 in Amsterdam
At SmallSat Europe, KenCast CEO Henrik Axelsson presented on resilient data delivery for SmallSat and hybrid space–ground architectures. An accompanying six-page IEEE technical paper is available upon request. The overview below distills the central problem and the techniques KenCast uses to address it.
The core challenge is that SmallSat missions increasingly depend on time-sensitive data, while the links used to deliver that data are often constrained, intermittent and loss-prone. In these environments, incomplete reception is not unusual. It is expected.
The question is how to reconstruct useful mission data when reception is fragmented across loss, gaps, paths and time.
Time-Sensitive Mission-Critical Data
SmallSat missions increasingly support data products whose value depends on timely delivery.
SAR and remote sensing products may be large and constrained by limited downlink opportunities. ISR data can lose operational value as conditions change. Onboard-processed outputs may be difficult to recreate. AI-ready products depend on usable, complete inputs. PNT-related data can become stale quickly.
In these cases, late or incomplete data may not simply be inconvenient. It may no longer serve the mission.
Why SmallSat Links Are Loss-Prone
SmallSat platforms often have less margin for changing link conditions.
Limited onboard power can constrain transmit strength. Smaller antennas can reduce link budget. LEO passes create short and changing visibility windows. Speed affects elevation, range and signal quality. Return paths may be limited, delayed or unavailable.
That means missing packets may not be easy to repair through ordinary retransmission. By the time a receiver knows what it missed, the contact window may be over.
Fragmented Reception Is the Norm
In SmallSat and hybrid delivery environments, receivers rarely receive a complete object all at once.
A receive site may collect only part of a file, stream segment or mission product. Loss may be uneven or bursty. Packets may arrive out of sequence. Different receivers may receive different subsets of the same transmission.
The practical reality is that receiver-side data is often incomplete, uneven and fragmented.
Hybrid Architectures Increase Variability
Hybrid GEO, LEO and terrestrial architectures add flexibility, but they also add variability.
A GEO path may provide broad coverage and longer visibility, but with higher latency. A LEO path may offer lower latency, but with shorter contact windows and more frequent handovers. Terrestrial paths may provide high throughput where available, but uneven geographic reach.
As data moves across these different paths, receivers may accumulate different pieces of the same data object over time. Recovery therefore needs to work across paths, sessions and contact windows, not only within a single clean transmission.
Why Conventional Recovery Models Break Down
Traditional recovery approaches depend on assumptions that may not hold in SmallSat and hybrid multicast environments.
Retransmission needs timely feedback. Block FEC protects fixed packet groups. Repetition or carousel delivery may resend data that receivers already have while still leaving other gaps unresolved. In multicast environments, each receiver may miss different packets, making repair increasingly receiver-specific.
The bottleneck becomes dependence on specific missing packets or fixed recovery groups.
Link-Layer FEC: Necessary, But Limited
Forward Error Correction adds redundancy so a receiver can correct some errors without requesting retransmission.
Link-layer FEC operates at or near the physical transmission layer, including modems, radios, waveforms or physical-layer standards. It helps protect against bit or symbol errors in the transmission link.
This protection is necessary. When a signal is present but degraded, link-layer FEC improves the chance that packets will be received correctly.
But link-layer FEC can only help with packets that arrive. It does not solve the problem of packets that are never received because of coverage gaps, handovers, mobility or the end of a contact window.
Application-Layer FEC Protects the Data Object
That is why the delivered data object also needs protection.
KenCast AL-FEC operates above the physical transmission layer and protects the file, stream segment or mission data product itself. It allows useful received data to be retained and combined with later reception from another path, pass, session or contact window.
The receiver does not need to discard partial reception simply because the full object did not arrive in one pass. Instead, partial reception becomes useful recovery progress.
KenCast Smart FEC Enables Accumulation
SmartFEC extends this model.
Traditional delivery often depends on receiving specific missing packets. If the receiver is still waiting for the wrong packet, reconstruction can stall.
SmartFEC changes the dependency. Receivers accumulate useful recovery data derived from the original object. Packets can arrive in any order, over different paths and across different sessions. Once enough useful recovery information has been received, the data object can be reconstructed.
This is especially important in SmallSat and hybrid architectures, where a receiver may not get a clean, complete transmission in one contact window.
Resilient Delivery Across Gaps, Paths and Loss
SmallSat and hybrid architectures will continue to operate under constrained and variable conditions. Links will be intermittent. Loss will occur. Receivers will not always share the same packet history.
The goal is not to eliminate every lost packet. The goal is to make loss manageable.
By combining application-layer FEC, time-distributed redundancy and rateless recovery, KenCast helps turn fragmented reception into reconstructed mission data across gaps, paths and sessions.
KenCast SmartFEC helps protect mission data where link-layer protection alone is not enough.
